/*
 * Copyright (C) 2011 Thomas Akehurst
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.github.tomakehurst.wiremock.http;

import com.fasterxml.jackson.annotation.JsonProperty;

import java.util.concurrent.ThreadLocalRandom;

/**
 * Distribution that returns values uniformally distributed across a range.
 *
 * That is, given a uniform distribution of 50 to 60 ms, there will be an equal
 * spread of delays between 50 and 60. This would useful for representing an
 * average delay of 55ms with a +/- 5ms jitter.
 */
public final class UniformDistribution implements DelayDistribution {

    @JsonProperty("lower")
    private final int lower;

    @JsonProperty("upper")
    private final int upper;

    /**
     * @param lower lower bound inclusive
     * @param upper upper bound inclusive
     */
    public UniformDistribution(@JsonProperty("lower") int lower, @JsonProperty("upper") int upper) {
        this.lower = lower;
        this.upper = upper;
    }

    @Override
    public long sampleMillis() {
        return ThreadLocalRandom.current().nextLong(lower, upper + 1);
    }
}
